Is the Audio research ref75se enough power for the sopra no2?
 

Hi guys,
I'm using arc ref75se driving sonus faber olympica lll for a year now and noticed that the amp is not efficient enough for the O3's. At high volume the O3's sound strained and harsh. The amp is 75wpc push pull tube class ab and the O3's nominal impedance is 4ohm and sensitivity is 90db claimed but actually is 88.8db measured by hifi news mag. Is this because 4ohm speakers are hard to drive then an 8ohm speakers? Room size is 15' x 15' only.

I'm thinking of changing it to the sopra no2, which is 8ohm and 91db claimed but actually is 88.7db mesured by hifi news mag. My worry is would the arc ref75se have enough power for the sopra no2?

Anybody please help, as I'm going to put a deposit on sopra no2 by tomorrow.

If you have a dealer with the sopra no2, will he let you bring in your ARC 75se to try?

The dealer does not have the sopra no2 for demo. They only have no1.

Well ... how close spec-wise is the 2 to the 1? If the 1 is near 90db efficiency and 8 Ohms, the ARC 75se may work fine - it is a sweetheart of an amp. You talk about problems at loud volumes with your other focals - what does that mean. What sort of music do you listen to at loud volumes? I have no familiarity with Focals, just trying to suggest in case you find no one with direct experience? Unless you're willing to change amps, I'd do a bit more research on the combination before ordering.

The speakers im using now are not Focals, it's Sonus Faber Olympica lll.
I listen to all kinds of music like jazz, blues, slow rock, rnb, electronic etc...

Your system is very similar to mine and I have no issues with the 75SE running out of steam. In fact the meters rarely deflect to mid point except at unpleasant volumes. Before buying new speakers try to get a loaner on an ARC Ref 150 as means of logically trying to diagnose your concerns of inadequate power. Keep the variables to a minimum to achieve useful, interpretable, results.

I'm a big Sopra 2 fan but I can't imagine just plopping down $15K on a loudspeaker based on what a stranger tells you on the internet. Demoing a Sopra 1 (a bookshelf speaker) is not going to tell you how a Sopra 2 sounds. If you can't demo a speaker you're interested in, find another dealer who does or wait until they can get one in to demo. Forgetting for a moment the measurements that you're concerned with (impedance/efficiency) the Focals are *very* different in sound to the OIII. Even if they fix the issue you're having at high volumes, that might not matter if you don't like the sound of the speakers. I agree wholeheartedly with tima. Take the time and research before ordering speakers you've never heard. You've lived with the OIII for a year now. What's a little more time going to matter?

Not quite apples to apples but I am driving the Sopra No. 3's with a Reference 150 in a medium size room (14'x24'). I would imagine the Reference 75SE would also do well because the power difference isn't that huge, but as others have said, you should do your own audition if at all possible. Also keep in mind that the sense of loudness you get from an amplifier doesn't always correlate 100% with the rated power. My Reference 150 can play significantly "louder" than other amps with similar power.

The kind of music you listen to will also make a significant difference. The dynamics required by much large orchestral classical music will stress an amp far more the jazz at comparable listening levels.